【作者】 彭仕尧；

【导师】 徐建民； 莫晓勇； 房桂干；

【作者基本信息】 中国林业科学研究院 ， 林木遗传育种， 2013， 博士

【摘要】 本研究以135个尾叶桉及其杂种无性系为对象，在桉树主栽区雷州林业局3种立地条件下多地点、多年度重复筛选优良无性系的基础上，对5年生适应、高产和抗风的尾细桉等杂种无性系开展了生长性状、木材材性和化学组分及其制浆性能的研究，经科学统计分析筛选出了一批具有推广应用价值的优良无性系。论文最终获得以下结论：（1）135个桉树无性系年均单位材积生长量排名前3位的是LL70号、LL53号和A01号，分别为37.64、33.62和30.79m³.hm^-2.a^-1。生长性状重复力在0.8569⁰.8932之间，在10%入选率下，性状遗传增益可达13.89%⁷7.46%，多数性状重复力较高，表明性状受到较强的遗传控制；41个尾细桉无性系重复力在0.8344⁰.9380之间，在12%入选率下，性状遗传增益达13.00%⁴4.40%；135个无性系以10%入选率筛选，入选的14个材积生长量最优无性系是LL70、LL53、A01、LH5、LL244、BP1、LL246、LL241、LL59、LL123、LH4、JJ53、LH1和LL120。3个地点的无性系生长表现，以唐家和石岭林场两个林场较好，北坡林场生长较差。通过多点适应性评价，不同无性系适宜不同的立地条件；稳定性评价将41个无性系分为四类，即高产稳定型19个、高产不稳定型5个、低产稳定型7个及低产不稳定型11个家系。（2）木材材性测定，135个无性系平均树皮率为15.24%；44个无性系的平均木材基本密度为482kg.m^-3；11个无性系纤维长度排名前3位的是A16、A07和A18；纤维长宽比平均值为41.50，排名前3位分别为A16、A15和A18；细小纤维含量排名前3位的分别是A18、A07和A01。综合11个无性系的材性分析表明，A18、A15和A01材性优良。（3）11个桉树无性系化学组分和制浆性能，灰分、1%NaOH热水抽出物含量、苯醇抽出物含量、聚戊糖含量、综纤维素含量和木素含量平均值分别为0.52%、2.09%、12.32%、0.73%、20.84%、82.74%和24.66%。11个无性系化学组分和制浆性能坐标综合评定法评定筛选最优的3无性系是LL67、A16和A20，对照ZU6排第5位。（4）尾细桉LH1和ZU6无性系，其纤维长度、宽度和长宽比均随树龄呈增加趋势，纤维长度在0.6⁰.8mm之间，长宽比在34.4⁴2.4之间，同龄LH1的长宽比高于ZU6；随林龄增加木材质量和制浆造纸性能提高。ZU6、LH1灰分含量在0.5%¹.1%之间，有随树龄增加而下降的趋势；ZU6及LH1的苯醇抽出物含量在0.5％¹.1％之间，以3年生ZU6的苯醇抽出物含量最高为1.09%，4年生LH1的苯醇抽出物含量最高为0.87%。1%NaOH抽出物含量随树龄呈下降趋势，ZU6高于LH1。随树龄变化，ZU6及LH1聚戊糖含量变化不明显，以ZU6稍高。无性系综纤维素含量随树龄呈上升趋势至第4年后基本保持不变，4年生桉木综纤维素含量已接近82%；木素含量随树龄变化略有上升；制浆得率及抗张指数随树龄呈上升趋势，LH1制浆得率在60%⁶5%之间，明显高于ZU6；2³年生LH1化学浆抗张指数略高于ZU6，4⁵年生两者的抗张指数几乎相等，达到64.5N.m.g-1；桉树木粉白度在30%ISO左右，随树龄增加ZU6及LH1木粉白度总体增加，3年生ZU6白度最高，4年生LH1白度最高，综合比较以LH1木粉白度较高。制浆性能综合比较，以LH1优于ZU6。（5）综合木材材性和化学组分的分析，尾细桉A15是满足选育目标的优良无性系，其材性综合排名第2位，化学组分和制浆性能排名第4位，是最适雷州推广应用的尾细桉优良无性系。（6）综合分析135个桉树无性系受风害影响，低于15%受害率的桉树无性系有11个，以赤桉纯种无性系抗风性最优，11个无性系中尾细桉无性系有3个，分别是LL91、LL77和LH3。因此，根据人工林风害影响在自然选择基础上可筛选出11个抗风无性系，它们分别是LL81、LL79、LL90、LL92、LL60、BP17、LL53、LL91、LL77、LL61和LH3，其平均风害率在7¹3.9%之间。（7）77个无性系青枯病感染死亡率变幅在0⁴1.7%之间。其中死亡率为0的15个无性系中，尾细桉无性系8个、赤桉无性系4个，分别是A01、BP22、LH1、LH4、LL123、LL244、LL246、LL62、LL71、LL81、LL98、SH7、SX9、TJ29和ZU6。因青枯病与风害具有较强的相关性，故其无性系选择结果基本相似，综合分析表明无性系遗传组成中含有细叶桉和赤桉遗传成分的无性系，其抗风性和抗青枯病能力均表现较强，具重要的利用价值。（8）经对生长、材性及化学组分的全面分析，以坐标综合评定法和平均隶属函数法两种方法对42个无性系进行评定，坐标法评定最优5个无性系为LH5、LL53、LL70、LH4和LL59，对照ZU6排第15位；隶属函数法评定最优5无性系为LH5、LL70、LH4、LL53和LL59，对照ZU6排第28位。两比较种评定方法发现，评定的前10名优良无性系有9个相同，它们是LH5、LL53、LL70、LH4、LL59、LL91、LL67、LH3和LL81，其中6个无性系为尾细桉杂种无性系，表明通过两种方法获得的最优9个无性系选择具有较强的可靠性，是今后纸浆林培育最具推广应用价值的优良无性系和育种基因资源。（9）结合大径材培育要求：高产、材质优和抗逆性强等特性，如在雷州半岛及周边筛选区域性的优良无性系，今后需对入选无性系开展进行进一步观测、选择和研究。更多还原

【Abstract】 Eucalyptus urophylla×E. tereticornis hybrids were researched by Eucalyptus introduction, breeding and improvement in Leizhou Forestry bureau since1980s. By the investigation and analysis data, different E. urophylla×E. tereticornis clones have been studied on growth, wood properties，wood chemical component，pulping properties and resistant level for the excellent clones selection. The objection of all the research is to findmore better clones for sustainable breeding, cultivation, popularization and applicationconstantly which can improve afforestation efficiency of ecology, society and economy.The main conclusions are as follows:（1）The best3clones are LL70, LL53and A01in the135clones according to the mean AHCI value（average growth increment per hectare in one year）, and the value are37.64,33.62and30.79m³.hm^-2.a^-1, respectively. The repeatablity of all growth traits of135clones are0.8569⁰.8932, the genetic gain can reach13.89%⁷7.46%and the excellent clones can be selected including of LL70, LL53, A01, LH5, LL244,BP1, LL246, LL241, LL59, LL123, LH4, JJ53, LH1and LL120at10%selected rate,and it indicated that the repeatablity value are very high and the growth traits have been affected sorely by the parents. The repeatablity of all growth traits of41E. urophylla×E. tereticornis clones are0.8344⁰.9380and the genetic gain can reach14.77%⁵3.28%at12%selected rate. The sites analysis results indicated that Tangjia and Shiling are better than Beipo among3forestry farm according to the clone growth level. According to the effect of adaptability and stability analysis of clones in3-site trial,41clones could be classified into4groups that had been named high-yeild and stable-growing group including of19clones, high-yeild and unstable-growing group including of5clones, low-yeild and stable-growing group including of7clones, low-yeild and unstable-growing group including of11clones. High-yeild and stable-growing group was fit for excellent-family selection and generalization.（2）Average BR （bark rate%） is15.24%of all135clones in wood properties; Average wood base density is482kg.m^-3of44clones; The3best clones of FL （Fiber length） value are A16, A07and A18in11clones, and the3best clones of FL/W （fiber length/width） value is are A16, A15and A18. The3best clones are A18, A07andA01according to the value of AFC%（Arithmetic fiber content/%）. Synthesis analysisaccording to the wood properities indicated that A18, A15and A01are the best clonesin11clones.（3）Average value of ash%, HWE%（hot water extractive%）,1%NaOH extracitve%, benzene ethanol extractive%, pentosan content％, holocellulose content％and lignincontent％are0.52%、2.09%、12.32%、0.73%、20.84%、82.74%和24.66%according tothe wood chemical component and pulping properties of11E. clones, respectivly. By traits value of taxis of11clones coordinate assessment the3most excellent clones areLL67, A16and A20，but the clontrol clone ZU6is the5thtaxis in11clones.（4）With two kinds clones of Eucalyptus urophylla×E. tereticornis as the experimental materials including of LH1and U6, basic density, fiber morphology and chemical components were determined and analyzed to study the relatioship between wood properties and tree age. The results showed that the FL, FW（fiber width）, FL/W value, pulp yield%, tensile index and wood brightness%can improve with the ages. The valueof FL and FL/W are0.6⁰.8mm and34.4⁴2.4, and the LH1is higher than ZU6including of the properities of FL, FL/W, pulp yield%and tensile index at the same age.The value of E. holocellulose content%, tensile index and brightness is82%,64.5N.m.g-1and30%ISO respectively. With the increasing of tree age, basic density and holocellulose content%rises while ash%and1%NaOH extractive%drops. Basic density of U6and LH1of five years are about443kg.m^-3and474kg.m^-3respectively, which would be better for optimal output, little effects of impregnation. The ash%of U6and LH1is about0.5^-1.1%, Length-width ratio is lower than45, which would be harmful for strength properties of paper. With the comprehensive comparison of pulp yield and tensile strength between U6and LH1, pulping performance of the LH1is better than U6.（5）Synthesis analysis according to the wood properities, wood chemical matter content and pulping performance indicated that A15clone is the best clones in all11Eucalyptus urophylla×E. tereticornis clones for the2ndtaxis of wood properites, the4thtaxis of chemical matter content and pulping performance.（6）Comprehensive analysis the effect of wind-damaged of135clones indicated that resistant ability of11clones are higher than others, and those are LL81, LL79, LL90, LL92, LL60, BP17, LL53, LL91, LL77, LL61and LH3E. clones including of3Eucalyptus urophylla×E. tereticornis clones such as LL91, LL77and LH3. Average value of wind-damaged rate is7¹3.9%.（7）Average Mortality rate of77clones is0⁴1.7%because of Pseudomonas solanacearum infection, and there are15clones that mortality rate are0including of8Eucalyptus urophylla×E. tereticornis and4E. camaldulensis clones. All the15clones are A01, BP22, LH1, LH4, LL123, LL244, LL246, LL62, LL71, LL81, LL98, SH7, SX9,TJ29and ZU6. There are more relativity and same effects between Pseudomonas solanacearum influence and wind-damaged for E. clones, so synthesis analysis the effect ofwind-damaged and Pseudomonas solanacearum infection indicated that the clones if itis from parents of E. tereticornis and E. camaldulensis will have a strong resistant forthe2kinds of harms and an important exploitated value for breeding.（8）By the methods of coordinate assessment and synthetically membership functionto synthesis analysis the42clones traits including of growth, wood properites and chemical composition, there are5best clones to be selected respectively. The5best clones are LH5, LL53, LL70, LH4and LL59by coordinate assessment method, and the5best clones are LH5, LL70, LH4, LL53and LL59by synthetically membership function method. The control clone ZU6is the15thor18thtaxis among42clones respectively. Compare to the2methods, there are9same clones in the10best clones and thos e are LH5, LL53, LL70, LH4, LL59, LL91, LL67, LH3and LL81. Of the10best clones there are6Eucalyptus urophylla×E. tereticornis clones can be popularized and applicated in resistance breeding and clones propagation in future for those good traits.（9）Combinating of high wood yeild, better wood properites and stronger resistant, there are more better clones can be selected in production for afforestation in Southern China. If progeny can inheritance such forgoing better traits, the gene-resource values will improve E. industry for more efficiency of ecology, society and economy by geneticbase collection and continuous breeding.更多还原